ceph: fix flushing caps
Current ceph_fsync() only flushes dirty caps and wait for them to be
flushed. It doesn't wait for caps that has already been flushing.
This patch makes ceph_fsync() wait for pending flushing caps too.
Besides, this patch also makes caps_are_flushed() peroperly handle
tid wrapping.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index a80a899..e9b03b5 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1097,8 +1097,7 @@
* caller should hold snap_rwsem (read), s_mutex.
*/
static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
- int op, int used, int want, int retain, int flushing,
- unsigned *pflush_tid)
+ int op, int used, int want, int retain, int flushing)
__releases(cap->ci->i_ceph_lock)
{
struct ceph_inode_info *ci = cap->ci;
@@ -1170,8 +1169,6 @@
* first ack clean Ax.
*/
flush_tid = ++ci->i_cap_flush_last_tid;
- if (pflush_tid)
- *pflush_tid = flush_tid;
dout(" cap_flush_tid %d\n", (int)flush_tid);
for (i = 0; i < CEPH_CAP_BITS; i++)
if (flushing & (1 << i))
@@ -1724,7 +1721,7 @@
/* __send_cap drops i_ceph_lock */
delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, cap_used,
- want, retain, flushing, NULL);
+ want, retain, flushing);
goto retry; /* retake i_ceph_lock and restart our cap scan. */
}
@@ -1753,12 +1750,12 @@
/*
* Try to flush dirty caps back to the auth mds.
*/
-static int try_flush_caps(struct inode *inode, unsigned *flush_tid)
+static int try_flush_caps(struct inode *inode, u16 flush_tid[])
{
struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
struct ceph_inode_info *ci = ceph_inode(inode);
- int flushing = 0;
struct ceph_mds_session *session = NULL;
+ int flushing = 0;
retry:
spin_lock(&ci->i_ceph_lock);
@@ -1787,17 +1784,19 @@
/* __send_cap drops i_ceph_lock */
delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH, used, want,
- cap->issued | cap->implemented, flushing,
- flush_tid);
- if (!delayed)
- goto out_unlocked;
+ cap->issued | cap->implemented, flushing);
spin_lock(&ci->i_ceph_lock);
- __cap_delay_requeue(mdsc, ci);
+ if (delayed)
+ __cap_delay_requeue(mdsc, ci);
}
+
+ flushing = ci->i_flushing_caps;
+ if (flushing)
+ memcpy(flush_tid, ci->i_cap_flush_tid,
+ sizeof(ci->i_cap_flush_tid));
out:
spin_unlock(&ci->i_ceph_lock);
-out_unlocked:
if (session)
mutex_unlock(&session->s_mutex);
return flushing;
@@ -1806,19 +1805,22 @@
/*
* Return true if we've flushed caps through the given flush_tid.
*/
-static int caps_are_flushed(struct inode *inode, unsigned tid)
+static int caps_are_flushed(struct inode *inode, u16 flush_tid[])
{
struct ceph_inode_info *ci = ceph_inode(inode);
int i, ret = 1;
spin_lock(&ci->i_ceph_lock);
- for (i = 0; i < CEPH_CAP_BITS; i++)
- if ((ci->i_flushing_caps & (1 << i)) &&
- ci->i_cap_flush_tid[i] <= tid) {
+ for (i = 0; i < CEPH_CAP_BITS; i++) {
+ if (!(ci->i_flushing_caps & (1 << i)))
+ continue;
+ // tid only has 16 bits. we need to handle wrapping
+ if ((s16)(ci->i_cap_flush_tid[i] - flush_tid[i]) <= 0) {
/* still flushing this bit */
ret = 0;
break;
}
+ }
spin_unlock(&ci->i_ceph_lock);
return ret;
}
@@ -1871,7 +1873,7 @@
{
struct inode *inode = file->f_mapping->host;
struct ceph_inode_info *ci = ceph_inode(inode);
- unsigned flush_tid;
+ u16 flush_tid[CEPH_CAP_BITS];
int ret;
int dirty;
@@ -1883,7 +1885,7 @@
return ret;
mutex_lock(&inode->i_mutex);
- dirty = try_flush_caps(inode, &flush_tid);
+ dirty = try_flush_caps(inode, flush_tid);
dout("fsync dirty caps are %s\n", ceph_cap_string(dirty));
/*
@@ -1892,7 +1894,6 @@
* wait for that)
*/
if (!datasync && (dirty & ~CEPH_CAP_ANY_FILE_WR)) {
- dout("fsync waiting for flush_tid %u\n", flush_tid);
ret = wait_event_interruptible(ci->i_cap_wq,
caps_are_flushed(inode, flush_tid));
}
@@ -1911,14 +1912,14 @@
int ceph_write_inode(struct inode *inode, struct writeback_control *wbc)
{
struct ceph_inode_info *ci = ceph_inode(inode);
- unsigned flush_tid;
+ u16 flush_tid[CEPH_CAP_BITS];
int err = 0;
int dirty;
int wait = wbc->sync_mode == WB_SYNC_ALL;
dout("write_inode %p wait=%d\n", inode, wait);
if (wait) {
- dirty = try_flush_caps(inode, &flush_tid);
+ dirty = try_flush_caps(inode, flush_tid);
if (dirty)
err = wait_event_interruptible(ci->i_cap_wq,
caps_are_flushed(inode, flush_tid));
@@ -1988,7 +1989,7 @@
__ceph_caps_used(ci),
__ceph_caps_wanted(ci),
cap->issued | cap->implemented,
- ci->i_flushing_caps, NULL);
+ ci->i_flushing_caps);
if (delayed) {
spin_lock(&ci->i_ceph_lock);
__cap_delay_requeue(mdsc, ci);
@@ -2027,7 +2028,7 @@
__ceph_caps_used(ci),
__ceph_caps_wanted(ci),
cap->issued | cap->implemented,
- ci->i_flushing_caps, NULL);
+ ci->i_flushing_caps);
if (delayed) {
spin_lock(&ci->i_ceph_lock);
__cap_delay_requeue(mdsc, ci);